The New Zealand Law Society is investigating a complaint over the way a former top barrister and prosecutor was treated in the Auckland District Court this week.

David Lloyd-Barker wrote to the society's legal standards officer, Paul Byers, complaining that ex-Serious Fraud Office chief prosecutor Anita Killeen was never made to enter the dock, sat alongside her QC Paul Davison and was never made to stand when being sentenced.

Mr Davison asked Judge Mary Beth Sharp in advance if the defendant could sit beside him, rather than in the dock.

The judge indicated she would allow Killeen to be seated in the area usually reserved for counsel and to be alongside her QC as he made pre-sentencing submissions on her behalf.

No discussion was held about her moving when it came time for the sentence to be handed down.

Mr Davison said little seating room was available in that court and he had seen other similar cases.

"I've had the same with other clients. It's a matter entirely for the presiding judge. It's not unusual for an accused person not to be required to go into the dock during sentencing."

But Mr Lloyd-Barker said he was unhappy with what he had seen in court when Killeen was discharged without conviction after she pleaded guilty to forgery charges which carry three- and 10-year jail sentences.

Adam Feeley, ex-chief executive of the Serious Fraud Office, also expressed surprise about her treatment, saying New Zealand had a legal system but not a justice system.

Mr Feeley said he had also spoken to police after the sentencing about how matters unfolded.

"These are not pleasantries normally afforded to people who commit crime. She didn't have to plead," he said, complaining that Mr Davison had instead pleaded on her behalf.

Under a section of the Sentencing Act, Killeen was acquitted, even though she pleaded guilty to both forgery charges. A sentencing indication hearing was held in October but all aspects were suppressed.

Mr Lloyd-Barker questioned the procedures followed this week.

"Ms Killeen was invited to sit next to her counsel at the table. I have never seen this happen before," he told Mr Byers.

"Secondly, Judge Sharp said Ms Killeen could be seated until she was actually sentenced. ... I do not understand why Ms Killeen was allowed to avoid standing or even sitting in the dock like every other prisoner," he complained.

He also admitted he had a personal interest, saying he had been general manager of the Auckland SPCA but was made redundant at a time when Killeen was on the board.